Chocolatey Creamy Cheesecake

1 cup (225 ml) chocolate wafer crumbs
1/4 cup (60 ml) butter, melted (1/2 stick)
3 8 oz (224 grm). packages Philadelphia cream cheese
1-1/4 cups (300 ml) sugar
1 tbsp (15 ml) all-purpose flour
1/2 cup (125 ml) Dutch processed cocoa powder
1 8 oz (224 grm). container sour cream
1-1/2 tsp (7 ml) pure vanilla extract
3 eggs
whipped cream, garnish
fresh berries, optional
toasted nuts, optional
powdered sugar, optional

Combine chocolate wafer crumbs and 1/2 stick melted butter and press into the bottom of a 9 inch springform pan.
Combine cream cheese, sugar and flour then beat well on medium speed.
Add in cocoa, sour cream and vanilla extract until well blended.
Add eggs one at a time, mix on a low speed until blended.
Pour the mixture into the springform pan with the crust.
Bake 10 minutes at 450 degrees (225 C.), then reduce the temperature to 250 degrees (125 C.) and continue to bake for another 40 minutes.
Remove and place on wire rack to cool slowly.
Refridgerate for several hours.
Serve with homemade thick and sweetened whipped cream.
Garnish with berries or toasted nuts and drizzle with chocolate sauce.
Dusting with powdered sugar and/or cocoa is a nice touch too.